A suspended implement

Abstract: The implement is of the type which is hinged to a carrier arm (5) for pivoting around an axis (4) transverse to the carrier arm (5) and which comprises a stopping device for preventing said pivoting. The stopping device comprises a first member (8) fastened to the implement (1) and a second member (11) fastened to the carrier arm (5), the two members (8,11) being mutually connected in such a way that they and in particular their connections with the implement (1) and the carrier arm (5), respectively, are movable relative to each other between two extreme positions and adapted to take up a mutual position, in which they block the movement, the stopping device comprising an activating means (13) for acting on at least one of the two members (8) in a direction towards the position, in which the movement is blocked.

Description: The present invention relates to an implement of the type which close to a vertical plane through the mass centre of the implement is hinged to a carrier arm for pivoting around an axis transverse to the carrier arm and which comprises a stopping device for preventing said pivoting, the carrier arm being hinged to a frame connectable with a tractor for swinging between an operating position and a transport position, wherein the stopping device comprises a first member fastened to the implement and a second member fastened to the carrier arm, the two members are mutually engaging in such a way that they and in particular their connections with the implement and the carrier arm, respectively, are movable relative to each other between two extreme positions, and that they are adapted to take up a mutual position, in which they block the movement. An implement of this art is known from DE-A-1 582 356. An implement of the above type is a lift-suspended mower. Such a mower generally comprises several rotating knife means placed in a row and is pivotally suspended in a carrier arm for being adjustable during operation to the surface of a field to be mowed. The mower in question is adapted in view of transport to be swung with its carrier arm to a raised position behind the vehicle, for instance a tractor, on which it is mounted. For such transport the uncontrolled swinging in relation to the carrier arm is undesirable, and the implement therefore comprises a stopping device, by means of which the mower can be locked relative to the carrier arm. However, the known stopping devices suffer from the drawback that they are manually operated and requires that the driver of the tractor leaves the tractor when switching to a transport position in order to activate the stopping device and consequently lock the mower relative to the carrier arm. The object of the invention is to provide an implement of the type mentioned by way of introduction, in which implement the stopping device is automatically activated, when the implement is switched to a transport position. From GB-A-2 157 936 is known a lift-suspended mower which at one side is hinged to a carrier arm for pivoting around an axis transverse to the carrier arm and which comprises a stopping device for preventing said pivoting. The stopping device comprises a sliding bolt and the possibility of automatically moving the sliding bolt to an unlocked position when the implement is in a mowing position is mentioned. However an enabling disclosure is not given. The object is met in that the stopping device comprises an activating means comprising a string which when pulled acts on at least one of the two members in a direction towards the position, in which the movement is blocked, said string being connected with the frame in such a way that it is pulled when the carrier arm is swung to the transport position. Hereby is achieved that the implement can move freely between the extreme positions, which will correspond to the requirement during operation, while the implement, if the activating means is activated during transport, will be locked by the stopping device. The stopping device preferably comprises a spring which acts on at least one of the two members in a direction away from the position, in which the movement is blocked. Hereby the stopping device is prevented from indadvertently blocking the movement, for instance during operation. In an embodiment one of the two members comprises a track with a long leg and a short leg substantially perpendicular to one another, and said member is hinged to the implement or the carrier arm in such a way that the long leg of the track extends towards the hinge axis of the member and the short leg of the track extends transversely to the hinge axis of the member, and the second member comprises a pin adapted to engage the track, said pin being stationary relative to the carrier arm or the implement. The invention will be described in detail in the following by means of embodiments with reference to the drawing, in which Fig. 1 shows a lift-suspended mower in operating position, Fig. 2 the same mower in transport position, and Fig. 3 a view corresponding to Fig. 2, but showing a different embodiment of the stopping device. The drawing shows a mower 1 with two knife drums 2 suspended in a machine frame 3. The machine frame 3 is by means of a centrally placed hinge 4, the axis of which extends substantially horizontally in the operating position of the mower, suspended in a carrier arm 5, which is in turn hinged to a carrier frame 6 around a vertical axis 7. The carrier frame 6 may for instance be fastened to the rear lift arms of a tractor. By moving the carrier frame up and down the mower 1 may be moved between a lower operating position and an upper transport position with free height above the ground. While the mower 1 in its operating position normally will be swung to the side of the tractor, it will in the transport position be swung behind the tractor, which in the figures can be seen from the position of the carrier frame 6 relative to the mover. While it is desirable that the mower during operation may swing freely in its hinge 4, such a movement is undesirable during transport. The mower 1 is therefore provided with a stopping device for blocking said movement during transport. The stopping device comprises in the embodiment shown in Figs. 1 and 2 a plate 8 fastended to the machine frame 3 by means of a hinge 9, the axis of which is substantially parallel with the axis of the hinge 4. The plate 8 comprises an L-shaped track 10 engaging a pin 11 fastened to the carrier arm 5. A spring 12 acts on the plate 8 in a direction away from the carrier frame, whereas a string 13 is fastenend to the carrier frame 6 in a point 14, which is situated in such a way relative to the axis 7 that by swinging the mower from the operating position shown in Fig. 1 to the transport position shown in Fig. 2 a pull is exerted in the string 13 so that the plate is loaded in a direction towards the carrier frame 6. The string is preferably resilient to prevent it from breaking in case of overloading. If the string is a wire, the resiliency is for instance attained by inserting a spring which has to be stronger than the spring 12 in order to overcome the spring power of the latter. Hereby is achieved that the pin 11, when the mower is in its operating position, may move freely upwards and downwards in the long leg of the track 10, whereas in the transport position shown in Fig. 2 it is locked in the short leg of the track 10, the swinging movement of the mower 1 in the hinge 4 being also blocked thereby. In the embodiment shown in Figs. 1 and 2, the mower 1 will automatically swing to the oblique position shown in Fig. 2, when it is lifted to the transport position on account of imbalance relative to the hinge 4. Thereby the pin 11 becomes relatively displaced in the track 10 against the corner of the L and will likewise move relatively into the short leg of the L, when, on account of the swinging to the operating position behind the tractor, the string 13 is pulled. In a variant of the embodiment shown in Figs. 1 and 2, the mower is balanced in such a way that it hangs horizontally when it is in its raised position. The track will in that case be shaped in such a way that the short leg extends somewhere from the middle of the long leg instead of extending from one end of the long leg. Fig. 3 shows another embodiment, in which the stopping device comprises two arms 15, 16 which are hinged together in the point 17 and are hinged to the machine frame 3 and the carrier arm 4, respectively. On one arm 15 a pin 18 is fastened, said pin abutting in the position shown the arm 16, thus preventing further movement. The spring 12 and the string 13 both attack the stopping device close to the point 17 in such a way that the spring 12 tends to make the two arms 15, 16 bend in their common hinge, whereas the string 13 when pulled tries to straighten the arms 15,16. This means that the mower 1 can swing freely relative to the carrier arm 5 as long as the string 13 is not pulled, i.e. when the mower is in its operating position, while pulling of the string 13 will make the arms 15, 16 straighten as shown in Fig. 3 and act like a rigid rod connection between the machine frame 3 and the carrier arm 5, thereby preventing the mower 1 from swinging in the hinge 4. It is to be understood that even if the invention has here been described in connection with a mower, it may be used in connection with any centre-suspended implement. It should moreover be understood that though the invention is here described in connection with a machine which swings in a horizontal plane between an operating position and a transport position, the invention can also be used in connection with a machine which swings in a vertical plane between an operating position and a transport position.

Claims: An implement of the type which close to a vertical plane through the mass centre of the implement is hinged to a carrier arm for pivoting around an axis (4) transverse to the carrier arm (5) and which comprises a stopping device for preventing said pivoting, the carrier arm (5) being hinged to a frame connectable with a tractor for swinging between an operating position and a transport position, wherein the stopping device comprises a first member (8; 15) fastened to the implement (1) and a second member (11; 16) fastened to the carrier arm (5), the two members (8, 11; 15, 16) are mutually engaging in such a way that they and in particular their connections with the implement (1) and the carrier arm (5), respectively, are movable relative to each other between two extreme positions, and that they are adapted to take up a mutual position, in which they block the movement, characterized in that the stopping device comprises an activating means comprising a string (13) which when pulled acts on at least one of the two members (8; 15, 16) in a direction towards the position, in which the movement is blocked, said string (13) being connected with the frame in such a way that it is pulled when the carrier arm (5) is swung to the transport position. An implement according to claim 1, characterized in that the stopping device comprises a spring (12) which acts on at least one of the two members (8; 15, 16) in a direction away from the position, in which the movement is blocked. An implement according to claim 1 or 2, characterized in that one of the two members (8) comprises a track (10) with a long leg and a short leg substantially perpendicular to one another, and that said member is hinged to the implement (1) or the carrier arm in such a way that the long leg of the track (10) extends towards the hinge axis of the member (8), and that the short leg of the track extends transversely to the hinge axis of the member (8), and that the second member comprises a pin (11) adapted to engage the track, said pin being stationary relative to the carrier arm (5) or the implement.

Inventors: FREUDENDAHL JORN, SKAU OLE, FREUDENDAHL, JORN, SKAU, OLE
Applicants: FREUDENDAHL J FAB AS, JF-FABRIKEN - J. FREUDENDAHL A/S
Application year: 1994
Main classification: A01B73
IPC codes: A01B73